<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>listenOnce</title>
</head>
<body>
    <button class="btn" id="btn">点击我</button>
    <script>
        const listenOnce = (el,type,handler) => el.addEventListener(type,handler,{ once:true });
        listenOnce(document.querySelector('#btn'),'click',() => console.log('hello,world'));
    </script>
</body>
</html>